👤

Cand david avea 9 ani,diana sora sa avea 15 ani.acum au impreuna 46 de ani.cati ani are fiecare urgent dau coroana

Răspuns :

9+x+15+x=46
2x+24=46
2x=46-24
2x=22
X=22:2
X=11

David=9+11=20 ani
Diana=15+11=26 ani

Verificare:20+26=46
9+x+15+x=46
2x=46-15-9
2x=22
x=11 ani are

9+11=20 ani are David
15+11=26 ani are Diana